The letter was read by Tom to all his classmates.
All his classmates were read the letter by Tom.
问题补充：
还有
1.I Won't Lend My Dictionary to anybody
2.he handed the English newspaper to me
3.Will you send the Christmas card to your cousin
My dictionary won't be lent to anybody.
The English newspaper was handed to me by him.
Will the Christmas card be sent by you to your cousin?
有不明白的请继续追问(*^__^*)